New Delhi: It was a cold and foggy morning in the national capital on Friday with the minimum temperature recorded at 4.8 degrees Celsius, three notches below the season`s average. "There was shallow to moderate fog in the morning. The sky will mainly be clear and there will be haze thereafter," an India Meteorological Department (IMD) official said.

With persistent cold conditions and moist westerly winds, the air quality in Delhi was recorded in the `very poor` category -- an improvement from `severe` category -- with the overall Air Quality Index (AQI) recorded at 333, according to the System of Air Quality and Weather Forecasting And Research said.

Major pollutants were PM10 and PM 2.5, which were recorded as `poor` and `very poor`. Due to foggy conditions in the morning, a total of 11 Delhi-bound trains were delayed by two to four hours. The visibility in the morning was 600 metres.

Humidity at 8.30 a.m. was recorded at 97 per cent -- a highly unfavourable condition for pollutants to disperse. The maximum temperature during the day is expected to hover around 21 degrees Celsius. On Thursday, the minimum temperature was recorded at six degrees Celsius, while the maximum settled at 21.2 degrees Celsius, both a notch above the season`s average.